Balanced mower

ABSTRACT

A mower having a stationary cutter bar and a sickle reciprocal thereon, and a drive which comprises a pitman connected to the sickel and driven by a crank which has a counterweight. The crank is connected by a flexible, preferably nylon, gear assembly to a counterbalancing counterweight. Both counterweights are arranged in a meshing relation and in planes parallel to the longitudinal axis of the sickle. Certain force couples and unbalancing forces are modulated by deflection of the plastic gear teeth.

United States Patent [191 Scarnato et al,

[ BALANCED MOWER [7S] inventors: Thomas J. Scarnato, Barrington;

Paul C, Gordon, Hinsdale; Robert Sorensen, Glen Ellyn; Craig Ml. Lawler,Downers Grove, all of Ill.

[73] Assignee: International Harvester Company,

Chicago, Ill.

[22] Filed: May 19, 1972 [21 1 App]. No: 254,979

[52] US. (ll 56/163, 56/296, 74/461 [51] Hm. Cl. A010 35/08, AOld 55/02[58] Field oi Search... 56/296, 297, 306, 16.2, 10.2, 56/163, 10.4,14.9; 74/603, 604, 590, 591, 443, 444, DIG. 10, 445

[56] References Cited UNlT ED STATES PATENTS 2,745,238 5/1956 Hopkins56/296 2,790,295 4/1957 Collins 56/296 2,942,483 6/1960 Evans et al.74/40 2,857,777 10/1958 Porter 74/432 3,241,391 3/1966 Borro, Sr. et al.74/445 Earn. 22, 1974 2,580,266 12/1951 Abgarian 56/l0.4 3,234,7182/l966 2,827,753 3/1958 3,000,226 9/l96l Muehlhausen 56/296 X FQREIGNPATENTS 0R APPLICATIONS 948,341 1/1964 Great Britain 74/461 PrimaryExaminer-Russeil R. Kinsey Attorney, Agent, or Firm-Dennis K. Sullivan;Floyd B. Harman I [5 7] ABSTRACT A mower having a stationary cutter barand a sickle reciprocal thereon, and a drive which comprises a pitmanconnected to the sickel and driven by a crank which has a counterweight.The crank is connected by a flexible, preferably nylon, gear assembly toa counterbalancing counterweight. Both counterweights are arranged in ameshing relation and in planes parallel to the longitudinal axis of thesickle. Certain force couples and unbalancing forces are modulated bydeflection of the plastic gear teeth.

9 Claims, 9 Drawing Figures PAIENIEUJANPPWM SHEET 1 I]? 3 PATENIEU JAN 22 i374 SHEEE 3 E)? 5 BALANCED MOWER DISCUSSION OF THE PRIOR ART In priorart devices the accepted arrangement for driving a pitman and sickle, isto provide a counterbalancing weight on the crank wheel opposite thecrank pin. This type of arrangement counterbalances the inertia forcesof the sickle at each end of the stroke of the sickle, and the system isunbalanced at all angles except for where the weight is in opposition tothe sickle. There are systems which employ oppositely rotatingcounterweights but these weights are displaced laterally of the sickleand require a complicated drive linkage or if driven by gears, suchgears are metalic and non-yielding. None of these arrangements utilizeflexible gear teeth to modulate the unbalancing forces.

SUMMARY OF THE INVENTION This invention is concerned with a novel drivefor a pitman type mower.

A specific object is to provide a drive wherein the parts are orientedin a novel compact arrangement and wherein they cooperated in aneffective manner to essentially counterbalance unbalancing forces suchas cause excessive destructive vibrations.

The invention comprehends a drive for a mower which incorporates a pairof counterrotating elements which are interconnected by a resilientdrive couple.

These and other objects and advantages inherent in and encompassed bythe invention will become more readily apparent from the specificationsand the drawings, wherein:

FIG. 1 is a front view of a mower and tractor assembly shown in outlineform incorporating the invention;

FIG. 2 is a fragmentary top view of the mower assembl FIG. 3 is an endview of the mower assembly;

FIG. 4 is an enlarged longitudinal sectional view taken substantially online 44 of FIG. 3;

FIG. 5 is a perspective front view of the tractor and mower assembly;

FIG. 6 is a side elevational view of the drive mechanism at the inwardstroke end of the sickle;

FIG. 7 is a side elevational view of the drive between the stroke endsof the sickle;

FIG. 8 shows the position of the drive mechanism at the outward strokeend of the sickle; and

FIG. 9 is a rear perspective view of the drive mechanism and mountingtherefor.

DESCRIPTION OF THE INVENTION The invention is shown in association witha tractor generally designated 2 comprising a longitudinal body 3 andfront and rear wheel and axle assemblies 4 and 5.

The tractor body houses a transmission power transfer gear trainconnected to a generally horizontal output shaft 6 which extendsforwardly beneath the body from a gear or pulley case 7 at the rear ofthe body to adjacent the forward end of the body and at its forward endis journaled to a support structure 10 which is secured in dependingposition from the body.

Part of this support is a casting designated 12 which at one end 13 fitsinto a jaw 14 provided at the inner end of a coupling frame 15. Anupright pin 16 secures the jaw with the frame so that the frame ismovable forwardly and rearwardly between the front and rear wheelassemblies. The adjustment of the position of the coupling frame isaffected by a stay rod 17 which at its rear end is hooked at 19 to theouter end of the coupling frame and is angled toward the tractorforwardly and at its forward end is threaded at 20 and extends through asupport 21 mounted beneath the tractor adjacent to its front end. A pairof nuts are threaded on end 20 and are suitably tightened againstopposite sides of the support 21.

A pair of counterrotating drive members 24, 25 are located in front ofthe support structure 10. The member 25 comprises a shaft 26 which isrotatably mounted in ajournal 27 on the casting 12 on a generallyhorizontal axis parallel with the power output shaft 6 and at the sidethereof opposite the coupling frame. The shaft 26 is keyed to acounterweight 29 to which a gear 28 is bolted. The gear 28 has teeth 29made of plastic, deformable material preferably nylon or the like. Teeth29 mesh with teeth 30 also of like material on a gear 31 which is boltedto a counterweight 32 which is keyed to shaft 6. The counterweight 32 isdisposed at one side of the axis of rotation of shaft 6 and at theopposite side of said axis of shaft 6. The counterweight 32 has a crank34 connected thereto extending parallel with shaft 6.

It will be noted that the counterweights 29 and 32 are essentiallyhalf-moon designs and intercollate with each other during rotation andare located in a common vertical plane parallel with the sickle 35 atone side of a pitman 36 which operates in a vertical plane parallel withthe plane of operation of the counterweights.

The pitman 36 has one end 37 journaled to the crank 34 and at its otherend 38 is connected by a universal coupling 39 to the sickle 35 forreciprocating the same upon the mower bar 40 which is pivotallyconnected on a fore and aft extending axis X-X to the outer end of thecoupling frame. Now it will be noted that adjustment of the stay rod orbar 17 is effected to position the pitman 36 and sickle 35 inlongitudinal alignment and parallel with the plane of operation of thecounterrotating and counterbalancing drive members. The location ofthese drive members 24, 25 in a vertical plane maintains thecounterbalance of the sickle even though it is gagged by tiltingupwardly about the axis XX when the gag and lifting linkage is actuated.

This linkage 50 comprises av pair of pivotally interconnected links 51and 52, the link 51 being curved and having its lower end pivotallyconnected as at 54 to the mower bar outwardly of the axis XX. The link52 is pivotally connected by pin 55 to the lower ends of a pair ofidentical complementary side by side arranged sections 57,58 of a bellcrank lever 59. The elbow of the lever 59 is pivoted at 62 on a pin 63at the upper end of an upright support lug 64. The sections 57, 58 areinterconnected at their other ends 65 by a pint 66 which holds a lowerchain loop 67 of chain 68 between sections.

The chain 68 is suitably connected either to a manual, hydraulic orother actuator (not shown) as well known, which is adapted to lift thechain and rotate the lever 59 in a counterclockwise direction. Thispivots the mower upwardly about axis XX to gag position until the pin 55engages the adjacent edge 70 of the support lug 64. Then the couplingframe is bodily raised upwardly with'the mower to clear obstructions andthe like.

It will be appreciated that in view of the foregoing disclosure, variousother forms of the invention will become readily apparent which wouldfall within the scope of the appended claims.

What is claimed is:

1. In a mower of the type having a cutter bar and a sickle reciprocalthereon, means for driving the sickle comprising a pitman connected atone end to the sickle, a pair of counterrotating balancing elements,only one of which has a crank connection with the end of the pitman fordriving said pitman, a counterweight on each element, saidcounterweights being disposed in a common vertical plane parallel withsaid sickle and gear means drivingly interconnecting said elements forrotating said counterweights in phased relation in opposition to themass of the sickle at each end of its stroke and in counterbalancingrelation to each other during the interval between the ends of eachstroke, at least one of said gear means comprising plastic teethcharacterized by being deflectible and effective to modulate forcecouples generated between said counterweights.

2. The invention according to claim 1 wherein both of said gear meanscomprise plastic teeth of the character described.

3. The invention according to claim 1 wherein said teeth are formed ofnylon.

4. The invention according to claim 1 and said each counterweightlocated on one side of the axis of rotation of its respective element.

5. ln a mower for a tractor of the type having front and rear wheels andan intervening longitudinally extending body, a support suspendedbeneath said body, a power input shaft journaled from said support, arotary drive element connected to said shaft for rotation in a verticalplane, said element having a crank at one side of its axis of rotationand a counterweight on the other side of said axis, a coupling armhaving one end pivotally connected to said support for swinging movementabout an upright axis, a mower connected to the other end of thecoupling frame and comprising a mower bar and a sickle reciprocalthereon, a stay rod adjustably connected at one end to the tractor andat its other end to the coupling frame, a single pitman connected at oneend to said crank and at the other end to said sickle, acounterbalancing element journaled for rotation in a vertical plane onthe support and having a counterweight at one side of its axis ofrotation, gear means interconnecting said elements for driving saidcounterweights in predetermined phase relation, said stay rod beingadjustable to swing said coupling frame and said mower transversely ofsaid pitman for alignment of the sickle therewith longitudinally andparallel to said vertical planes of said elements.

6. The invention according to claim 5 and said gear means being formedof deformable yielding material for modulating the effects of saidcounterweights.

7. The invention according to claim 6 and said counterweights disposedin interfitting relation in substantially common vertical planesubstantially parallel with the plane of operation of the pitman.

8. The invention according to claim 7 and said counterweights phased toadditively oppose the mass of the sickle and pitman at each end of thestroke of the sickle and to counterbalance each other in the intervalbetween said ends of the stroke.

9. A mower comprising a cutter bar and a sickle reciprocal thereon,means for reciprocating and counterbalancing said sickle comprising apair of counterrotating elements mounted to rotate on generallyhorizontal parallel axes and having counterweights, said counterweightsdisposed in close coupled interfitting relation in a common verticalplane substantially parallel to said sickle, gear means mounted to eachrespective element and having meshing relation for driving said elementsand phasing said counterweights to oppose the inertia of the sickle ateach end of its stroke and counterbalancing each other at all otherangular displacements, and said gear means being formed of deflectible,nonmetallic material adapted to temporarily yield under the influence ofthe inertia forces developed in the elements so as to modulate theseforces.

1. In a mower of the type having a cutter bar and a sickle reciprocalthereon, means for driving the sickle comprising a pitman connected atone end to the sickle, a pair of counterrotating balancing elements,only one of which has a crank connection with the end of the pitman fordriving said pitman, a counterweight on each element, saidcounterweights being disposed in a common vertical plane parallel withsaid sickle and gear means drivingly interconnecting said elements forrotating said counterweights in phased relation in opposition to themass of the sickle at each end of its stroke and in counterbalancingrelation to each other during the interval between the ends of eachstroke, at least one of said gear means comprising plastic teethcharacterized by being deflectible and effective to modulate forcecouples generated between said counterweights.
 2. The inventionaccording to claim 1 wherein both of said gear means comprise plasticteeth of the character described.
 3. The invention according to claim 1wherein said teeth are formed of nylon.
 4. The invention according toclaim 1 and said each counterweight located on one side of the axis ofrotation of its respective element.
 5. In a mower for a tractor of thetype having front and rear wheels and an intervening longitudinallyextending body, a support suspended beneath said body, a power inputshaft journaled from said support, a rotary drive element connected tosaid shaft for rotation in a vertical plane, said element having a crankat one side of its axis of rotation and a counterweight on the otherside of said axis, a coupling arm having one end pivotally connected tosaid support for swinging movement about an upright axis, a mowerconnected to the other end of the coupling frame and comprising a mowerbar and a sickle reciprocal thereon, a stay rod adjustably connected atone end to the tractor and at its other end to the coupling frame, asingle pitman connected at one end to said crank and at the other end tosaid sickle, a counterbalancing element journaled for rotation in avertical plane on the support and having a counterweight at one side ofits axis of rotation, gear means interconnecting said elements fordriving said counterweights in predetermined phase relation, said stayrod being adjustable to swing said coupling frame and said mowertransversely of said pitman for alignment of the sickle therewithlongitudinally and parallel to said vertical planes of said elements. 6.The invention according to claim 5 and said gear means being formed ofdeformable yielding material for modulating the effects of saidcounterweights.
 7. The invention according to claim 6 and saidcounterweights disposed in interfitting relation in substantially commonvertical plane substantially parallel with the plane of operation of thepitman.
 8. The invention according to claim 7 and said counterweightsphased to additively oppose the mass of the sickle and pitman at eachend of the stroke of the sickle and to counterbalance each other in theinterval between said ends of the stroke.
 9. A mower comprising a cutterbar and a sickle reciprocal thereon, means for reciprocating andcounterbalancing said sickle comprising a pair of counterrotatingelements mounted to rotate on generally horizontal parallel axes andhaving counterweights, said counterweights disposed in close coupledinterfitting relation in a common vertical plane substantially parallelto said sickle, gear means mounted to each respective element and havingmeshing relation for driving said elements and phasing saidcounterweights to oppose the inertia of the sickle at each end of itsstroke and counterbalancing each other at all other angulardisplacements, and said gear means being formed of deflectible,nonmetallic material adapted to temporarily yield under the influence ofthe ineRtia forces developed in the elements so as to modulate theseforces.